In the field of integrated circuits, small packages collectively known as integrated circuit devices contain large numbers of electrical circuits fabricated from semiconductors. These integrated circuit devices, have been constructed with external mounting features for mounting on a planar surface of a printed circuit board. Electrical circuit paths along layered surfaces of the circuit board electrically link together the integrated circuit packages.
In the construction of an electronic apparatus, for example, a computer, many such circuit boards, also called cards, plug edgewise into electrical connectors mounted on a back plane circuit board, for example, as described in U.S. Pat. No. 4,134,631. Many such cards are spaced apart from each other in a parallel array. This construction has been suitable for a computer that utilizes a single computer processor, particularly, a desktop computer. A computer with a single processor is able to perform a limited number of computer executions simultaneously, or in parallel. A larger computer utilizes multiple processors that are linked together, and that operate in concert, to perform massive numbers of parallel executions.
The multiple processors need to be linked together with a large number of electrical circuit paths, such that each processor will be linked to each of the others. Due to the processors being spaced apart from one another by relatively large distances, the electrical circuit paths, already large in number, must extend over such long distances to link each processor to each of the others. The circuit paths must be arranged along circuit routes that maintain desired electrical impedances, and that eliminate electrical influences that one circuit path induces upon another. It has been found that parallel cards, formerly used, have insufficient capacity for maintaining the number of electrical circuit paths and the specified electrical impedances for interconnecting multiple processors.
Computer processors are being designed with packages shaped as cubes, with each of the cubes being designed with multiple external surfaces and mounting features on the multiple external surfaces. Interconnection of the mounting features on the multiple surfaces is required.